libvlc 无法停止流式传输并导致 Qt 应用程序崩溃

Question

我正在使用 libvlc 在 QT 中创建一个流媒体应用程序，它将播放来自任何来源的 RTSP 流媒体。我已经创建了它并且它对我来说工作正常，除了每当我想关闭它时我的应用程序崩溃。我的代码如下。

ThreadVlc.h

<pre>
#ifndef THREADVLC_H
#define THREADVLC_H
#include <vlc\vlc.h>
#include <vlc\libvlc.h>
#include <QtGui>
#include <QWidget>
#include <QThread>
#include <QApplication>
class vlcOnQtPlayer : public QThread
{
Q_OBJECT
 bool isVideoPlayingCheck;
    libvlc_instance_t *libvlcInstance;
    libvlc_media_player_t *libvlcMediaPlayer;
    libvlc_media_t *libvlcMedia;
 QString rtspLink;
 QMutex mmutex;

public:
    vlcOnQtPlayer(WId parentWinId);
    void stop();
protected:
 void run();

public slots:
 void vlcOnQtSetLink(QString link);
 //void playRtspLink();
 int onVlcStreamCapture(QString imageSavePath);
private:
 WId windowId;
};
#endif

</pre>

ThreadVlc.cpp

<pre>

#include "ThreadVlc.h"
#include <QVBoxLayout>
#include <QPushButton>
#include <QFrame>
#include<iostream>
#include<QMessageBox>
using namespace std;
vlcOnQtPlayer::vlcOnQtPlayer(WId parentWinId) : QThread()
{

 mmutex.lock();
 windowId=parentWinId;
 mmutex.unlock();
 isVideoPlayingCheck=false;
}

void vlcOnQtPlayer::stop()
{
 //QMessageBox::warning(0,"Warning", "before libvlc_media_player_stop");
    libvlc_media_player_stop (libvlcMediaPlayer);
 QMessageBox::warning(0,"Warning", "After libvlc_media_player_stop");
 libvlc_media_player_release (libvlcMediaPlayer);
    libvlc_release (libvlcInstance);
 
}

void vlcOnQtPlayer::run()
{
 if(rtspLink!=NULL)
 {

 const char * const vlc_args[] = { "--no-audio","-vv" };
 libvlcInstance=libvlc_new(sizeof(vlc_args)/sizeof(vlc_args[0]), vlc_args);          
    
     //Create a new LibVLC media descriptor
 libvlcMedia = libvlc_media_new_location(libvlcInstance, rtspLink.toAscii());
    
    libvlcMediaPlayer=libvlc_media_player_new_from_media (libvlcMedia);


    // Get our media instance to use our window 
     libvlc_media_player_set_hwnd(libvlcMediaPlayer, windowId);//vlcOnQtVideoFrame->winId());
    
    // Play 
    libvlc_media_player_play (libvlcMediaPlayer);
    
    isVideoPlayingCheck=true;   
 //return 0;
 }
 else
  isVideoPlayingCheck=false;
  //return 1;
}

int vlcOnQtPlayer::onVlcStreamCapture(QString imageSavePath)
{
 const char *file_Path=imageSavePath.toLocal8Bit().constData();
 //Function to take the snap shot of the screen
 int i=libvlc_video_take_snapshot(libvlcMediaPlayer,0,file_Path,0,0);
 return i;
}


void vlcOnQtPlayer::vlcOnQtSetLink(QString link) 
{ 
 mmutex.lock();
 rtspLink=link;
 mmutex.unlock();
}



</pre>

ThreadVlcMainWindow.h

<pre>

  
 #ifndef THREADVLCMAINWINDOW_H 
 #define THREADVLCMAINWINDOW_H
  /* Including necessary classes*/
  #include <QtGui>
  #include <QMainWindow> 
  #include <QApplication>
  #include <ThreadVlc.h>
  #include <QThread>
  #include <QEvent>
 /* Proto type for the Main Window Class*/ 
 class streamParentClass : public QMainWindow 
 { 
  Q_OBJECT 
 public: 
  int count,noOfCam; // Variables for munber of cameras and counter
  streamParentClass(QWidget *parent = 0);
  ~streamParentClass();
  QWidget *centralWidgetWindow; //Window to be set as central widget (central widget of main window)
  QGridLayout *streamIfaceLayout;
  QFrame * streamFrame;
  vlcOnQtPlayer * streamPlayerInstance;

  //QList <QPushButton *>btn;
  void guiDesign(); //For basic design of controls
  void addStreamWin(int); // To add vlc instances to main window
  void closeEvent(QCloseEvent *);
 };

#endif



</pre>

ThreadVlcMainWindow.cpp

<pre>

#include "ThreadVlcMainWindow.h" 
 #include <QtGui>
 #include <QToolBar> 
 #include <QIcon> 
 #include <QAction> 
 streamParentClass::streamParentClass(QWidget *parent) : QMainWindow(parent) 
    {
  noOfCam=1;
  guiDesign();     //Initializing controls
  addStreamWin(noOfCam);
 }

 
 streamParentClass::~streamParentClass()
 {
  for(int i=0;i<noOfCam;i++)
  {
   streamPlayerInstance->stop();
   streamIfaceLayout->removeWidget(streamFrame);

  }
  
  qApp->quit();
 }
 void streamParentClass::guiDesign()
 {
  centralWidgetWindow=new QWidget(this);
  streamIfaceLayout=new huffnetInterfaceLayout(centralWidgetWindow,4);
  centralWidgetWindow->setLayout(streamIfaceLayout);
  setCentralWidget(centralWidgetWindow);

 }
 void streamParentClass::addStreamWin(int n)
 {    
   for(int i=0;i<n;i++)
   {   
       streamFrame=new QFrame(centralWidgetWindow);
    streamFrame->setWindowFlags(Qt::FramelessWindowHint);
    streamPlayerInstance= new vlcOnQtPlayer(streamFrame->winId());
    streamIfaceLayout->addWidget(streamFrame,0,0);
    connect(streamPlayerInstance,SIGNAL(finished()),streamPlayerInstance,SLOT(deleteLater()));
    streamPlayerInstance->vlcOnQtSetLink("rtsp://:8554/strm");
    streamPlayerInstance->start();
   }
    
 }
 
 
 void streamParentClass::closeEvent(QCloseEvent *event)
  {
   
   for(int i=0;i<noOfCam;i++)
   {
    streamPlayerInstance->stop();//~vlcOnQtPlayer();
    delete streamFrame;
    delete centralWidgetWindow;
   //QMessageBox::warning(0,"Warning", "Inside for "); 
   } 

   qApp->quit();
  }
     

</pre>

Main.cpp

<pre>

#include "ThreadVlcMainWindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
 QApplication app(argc,argv);
 streamParentClass mp;
 mp.resize(500,400);
 mp.show();
 return app.exec();
}

</pre>

我正在使用 Qt 4.8 和 Microsoft visual studio 2010 来构建它。它从服务器流式传输正常。我正在使用 Vlc Media Player 创建一个正在流式传输视频的流媒体服务器。但是当我试图关闭它时，它正在崩溃我的 window。我已经检查了几个错误并且喜欢 libvlc 无法处理命令 libvlc_media_player_stop() 。感谢您的任何建议。

Answer 1

找到代码中的主要问题。主要问题是由于多线程，因为当我们在 threadVLC.cpp 中调用 libvlc_media_player_stop() 时，多个线程无法通信.所以我们必须强制终止线程，或者我们必须跳过线程。 libvlc_media_player_stop() 工作正常。我在 videoLAN 论坛上搜索过它。 https://forum.videolan.org/viewtopic.php?t=106415

感谢 RSATom 向我推荐论坛。

libvlc 无法停止流式传输并导致 Qt 应用程序崩溃

libvlc is unable to stop streaming & causes crash in Qt Application

qt4

visual-studio-2010

libvlc